WiiPresent is a small program that enables you to use a Nintendo Wiimote
for giving presentations using Open Office, xpdf, evince or Acrobat Reader.
It was designed as an off-the-shelf tool with no need to customize it.

But WiiPresent can also control multimedia applications or firefox.
It does this by translating WiiMote events into keypresses for applications.

There were quite a few compelling reasons for using a Wiimote for giving
presentations:

the same features as most of the advanced presentation devices

is much cheaper (40 EUR) than those advanced presentation devices (>80 EUR)

has an open and documented interface where some advanced devices do not
work in Linux

uses bluetooth which is common on laptops nowadays, but small USB bluetooth
receivers are quite cheap (10 EUR)

works very reliably even in a big exhibition hall (LinuxTag 2008) with
thousands of people and booths with as many bluetooth devices. We even left
the exhbition room and we were still able to control our laptop at the
CentOS booth (witness references on request :-))

fancy silicon covers exist in various colors matching your outfit are
available from Ebay

at least one person attributes finding a girlfriend by using the wiimote in
a public area (name witheld because of privacy concerns)

they come with a wrist-cord (and anti-slip coating) for vivid, animated
presenters using lots of gestures